1. Field of the Invention
This invention pertains to a reusable rivet, which is formed by a two-shot molding process, wherein a central rotatable screw element drives a lower threaded collar of a body element so that folding legs extend into an engaged position.
2. Description of the Prior Art
In the prior art, rivets of various kinds are known. However, the installed position of many rivets includes the inelastic deformation of metal, so that removal of the rivet typically destroys the rivet so that subsequent use is not possible. Similarly, some rivets may include locking engagement which is not meant to be reversible so that the removal of the rivet requires that the rivet be torn or ripped in a way such that subsequent re-use is not possible.
Additionally, many rivets include two pieces which are manufactured and even shipped separately and assembled immediately prior to installation. Such a design increases the manufacturing, shipping and assembly costs.
Examples of prior art rivets may be found in U.S. Pat. No. 5,690,454 entitled xe2x80x9cAnchoring Retainer for Threaded Fastenersxe2x80x9d, issued on Nov. 25, 1997 to Smith; U.S. Pat. No. 4,776,737 entitled xe2x80x9cRe-Usable Two-Piece Blind Fastenerxe2x80x9d, issued on Oct. 11, 1988 to Wollar; U.S. Pat. No. 4,659,269 entitled xe2x80x9cFastening Dowel of Plasticsxe2x80x9d, issued on Apr. 21, 1987 to Stromiedel; and U.S. Pat. No. 4,274,324 entitled xe2x80x9cHollow Wall Screw Anchorxe2x80x9d, issued on Jun. 23, 1981 to Giannuzzi.
It is therefore an object of the present invention to provide a rivet which is reusable.
It is therefore a further object of the present invention to provide a rivet which minimizes inelastic deformations during installation.
It is therefore a still further object of the present invention to provide a rivet which can be removed from the installed position without damaging the rivet, and which can be re-used.
It is therefore a still further object of the present invention to provide a rivet which can be manufactured and shipped as a single unit.
It is therefore a still further object of the present invention to provide a rivet which can be installed and removed with standard tools, in an ergonomically intuitive manner.
These and other objects are attained by providing a rivet with a body element with a head and a lower internally threaded collar. which are joined by foldable legs. A screw element includes a screwhead and is rotatable but longitudinally stabilized within the head of the body. The screw element further includes a threaded shank with an enlarged lower end. The lower internally threaded collar is threadably engaged with the threaded shank and moves longitudinally bounded by the head of the body and the enlarged lower end of the threaded shank. When the lower internally threaded collar is against the enlarged lower end of the threaded shank, the legs of the body abut and are parallel to the threaded shank. This is the uninstalled position. However, as the internally threaded collar is driven toward the head of the body, the legs fold so as to be perpendicular to the threaded shank and thereby form the installed position.
The rivet is formed by a two-shot molding process, wherein the screw element is first molded from a glass filled nylon 6/6 or similar material, and then the body element is molded around the screw element from nylon 6/6 or similar material.